Oct. 13 (HealthDay News) -- Untreatable vision problems are associated with a shorter life span, Australian researchers have found.

Their study confirms previous findings that had linked vision impairment with an increased risk of death from such factors as accidental injury, depression, a low body mass index, slow walking speeds, a greater likelihood of falls, lower levels of physical activity, cardiovascular disease, dementia and cancer.

At the start of the study, which included 3,654 people age 49 and older, participants who were female, 75 and older and underweight were the most likely to have non-correctable impaired vision.

According to the findings, published in the October issue of the journal Archives of Ophthalmology, 1,273 study participants died in the 13 years after the study began. The researchers noted that people with non-correctable impaired vision had a higher risk for dying in that time period, and the association was strongest for those younger than 75.

The study "revealed greater effects of non-correctable visual impairment on mortality risk, with both direct and indirect effects," wrote Michael J. Karpa, of the Westmead Millennium Institute in Sydney, and his colleagues. "Of mortality risk markers examined, only disability in walking demonstrated a significant indirect pathway for the link between visual impairment and mortality."

The researchers concluded that the study "reaffirms that visual impairment is associated with an increased risk of all-cause mortality."

"Disability in walking may represent an important indirect pathway to mortality for persons with visual impairment, and adjusting for this factor in statistical analysis may overadjust for the indirect effect of visual impairment on mortality risk," they wrote. "The impact of visual impairment on mortality may in fact be greater than that reported from previous studies that have used traditional statistical models."

SOURCE: JAMA/Archives journals, news release, Oct. 12, 2009